To provide a soft X-ray microscope device that is not affected by a target fragment, can be used for a long time, and can be miniaturized.

The soft X-ray microscope device comprises: a table 10; a housing 20 that is disposed at the upper end of the table and includes a partition 22; and a light source chamber 30 that is disposed on the downside of the partition of the housing and radiates a light source to liquid injected at a high pressure to form plasma. This device also comprises a mirror chamber 40 that is disposed on the upside of the partition of the housing, first and second mirror sections 410 and 430 on the upside and downside of a holder section 420 for storing a biological sample, lights the biological sample with soft X-rays generated by the plasma formed by the light source chamber, amplifies the soft X-rays having transmitted through the biological sample, and allows video to be acquired by an imaging chamber. This device also comprises the imaging chamber 50 that is disposed at the upper end of the housing, amplifies a light video signal amplified by the mirror chamber, and images it on an external screen so as to allow identification on the outside.