We use income tax record to evaluate the impact of the 2007 minimum wage increase in Taiwan on low-wage workers. The policy is effective. Considerable proportions of directly affected workers received exactly the new minimum wage in 2008. However, we also find that minimum wage increase significantly reduced the probability of receiving an annual salary higher than the minimum wage. The average elasticity of our preferred estimation is -1.46, which means the 1% increase in minimum wage will reduce the probability -1.46%. The effects are larger on elders, females, workers of larger organizations, and workers from urban areas. Our results are robust to different choices of control groups and sample selection. Under the limitation of data, we cannot interpret the results explicitly and assert the welfare change.