To provide a study desk in which a storage space can be easily secured even if a personal computer is mounted.

In a bookshelf 10, a left partition plate 15L and a right partition plate 15R are arranged between a left side plate 12 and a right side plate 13 and a middle shelf plate 14C is mounted between the left partition plate 15L and the right partition plate 15R. The middle shelf plate 14C has a fixed shelf plate 14A fixed to a back plate 11 and a moving shelf plate 14B removably arranged, the moving shelf plate 14B is so formed to engage with a guide plate arranged with being protruded from the left partition plate 15L and the right partition plate 15R. Therefore, when employing a personal computer, accommodating space for the personal computer is formed by removing the moving shelf plate 14B.