The National Samsung Electronics Labor Union had instructed its 28,000 members to use paid leave on the day after wage negotiations with the management fell apart early last week.
The union, which represents 22 percent of the 125,000 employees of the world's largest maker of memory chips, did not disclose participation numbers.
Given the high factory automation levels and the day falling between a holiday and a weekend when many workers scheduled vacations, the Taiwanese market researcher TrendForce predicted little impact on DRAM and NAND flash output or shipments.
This marks the first-ever strike since Samsung’s founding in 1969. Lee Hyun-kuk, the union's vice president, said further actions are planned as "a first step toward our ultimate goal of an all-out strike."
The two sides have conducted wage negotiations since January but failed to narrow differences as the union demanded a 6.5 percent increase while management offered 5.1 percent.
The union secured the legal right to strike last month after member votes and labor board rulings. It announced the unprecedented strike on May 29, after bargaining broke down the previous day.
Samsung's group-level labor union criticized the electronics union's leadership after the announcement.
