The main purpose of this study is to analyze features of the poor working-class rapidly increased since the foreign exchange crisis and clarify the main factors to cause working-class poverty. In this study, working-class poverty is defined as 'employed working-class poverty' and 'unemployed working-class poverty.' Chi-square (χ²) was used to analyze the features of typical workin-class poverty and multinomial logit analysis to figure out the main cause of such poverty. Findings are summarized as two points. First, age, gender, and educational level were found to affect unemployed working-class poverty; age, educational level, and single-mother family had a strong effect on employed working-class poverty. This finding shows that the strongest factor to affect unemployed working-class poverty was gender and the one to affect employed working-class poverty was single-mother family. This finding also indicates that females have difficulty being competitive in the labor market, and even though they were hired, they are more likely to be in poverty after their spouse died and they got divorced. Hence, it is proposed that government needs to implement a policy to reduce regulations toward unemployed working-class females and to provide them with a diversity of jobs that accommodate their needs and demands. Second finding was that working-class who should support seniors, children, or disabled had a higher risk to be in poverty. While unemployed working-class poverty was associated with involvement in the labor market, employed working-class poverty is connected with the quality of jobs. Therefore, government needs to offer social well fares to support children and senior cares, and if such well fares are not available, it is necessary for government to produce the jobs with a certain level of incomes.