ended June 30, 2022, to KRW 1,296 during the six months ended June 30, 2023. Our revenue for both periods were relatively similar when compared in KRW. We had revenue of KRW 16,279,026,192 for the six months ended June 30, 2023, compared to KRW 16,536,396,525 for the six months ended June 30, 2022 (a decrease of 1.6%).
Cost of sales
Our cost of goods sold decreased by 8.0% to $6,327,732 for the six months ended June 30, 2023, compared to $6,878,593 for the six months ended June 30, 2022, mainly due to the weakening of KRW against USD as described above and a slight decrease in revenue for the six months ended June 30, 2023.
For the six months ended June 30, 2023, our cost of sales consisted primarily of labor cost of $1.00 million, outsourced cost of $0.38 million, cost of inventory movement of $3.54 million and others of $1.40 million.
For the six months ended June 30, 2022, our cost of sales consisted primarily of labor cost of $0.87 million, outsourced cost of $1.91 million, cost of inventory movement of $2.32 million and others of $1.78 million.
Gross profit
Gross profit decreased by 4.5% to $6,234,448 for the six months ended June 30, 2023 compared to $6,527,740 for the six months ended June 30, 2022, mainly due to the weakening of KRW against USD as described above. Gross profit for both periods were relatively similar when compared in KRW. We had gross profit of KRW 8,079,071,014 for the six months ended June 30, 2023 and KRW 8,051,814,062 for the six months ended June 30, 2022 (an increase of 0.3%).
Selling and administrative expenses -
Our selling and administrative expenses increased by 17.2% to $4,981,094 for the six months ended June 30, 2023, compared to $4,250,957 for the six months ended June 30, 2022. This increase was primarily caused by increases in amortization expense, commission and rent, by $372,444, $269,256, and $142,657, respectively, primarily caused by the consolidation of G-SMATT America for the six months ended June 30, 2023, but not for the six months ended June 30, 2022. On July 1, 2022, the Company’s ownership in G-SMATT America Co., Ltd increased by 12% from 42.63% to 54.63% and G-SMATT America has been subject to consolidation from the date of the majority ownership change in July 1, 2022.
For the six months ended June 30, 2023, our selling and administrative expenses consisted primarily of commission of $1,158,977, salaries of $1,141,405, amortization of $877,499, employee share compensation cost of $411,384, and depreciation of $147,364.
For the six months ended June 30, 2022, our selling and administrative expenses consisted primarily of salaries of $1,077,633, commission of $889,721, amortization of $505,055, ordinary research and development expenses of $166,635, depreciation of $219,667 and bad debt expense of $50,630.
Operating profit
Our operating profit decreased by 44.9% to $1,253,354 for the six months ended June 30, 2023, compared to operating profit of $2,276,783 for the six months ended June 30, 2022. The decrease was primarily caused by a significant increase in selling and administrative expense. Selling and administrative expense increased by $730,197 to $5.0 million for the six months ended June 30, 2023 from $4.3 million for the six months ended June 30, 2022. As a result, operating profit as a percentage of revenue decreased to 10% for the six months ended June 30, 2023 from 17% for the six months ended June 30, 2022.
Finance income
Our finance income decreased by 55.3% to $193,076 for the six months ended June 30, 2023, compared to $432,315 for the six months ended June 30, 2022, mainly because there was no recognition of gain from
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