The present invention provides a tissue dividing jig that can easily divide a needle biopsy tissue to be subjected to a biopsy over the entire length of the needle biopsy tissue. The tissue dividing jig includes: a tissue dividing base； and a cutting blade set. The tissue dividing base 301 has a tissue placement portion 302 on which a needle biopsy tissue S is to be placed. The cutting blade set 303 is provided with a cutting blade member 305 and a guide portion 307 (hinges). The tissue dividing base 301 and the cutting blade set 303 have a positioning mechanism 307 (hinges) for fixing their positions mutually. The cutting blade member 305 is provided with a cutting blade 306 that extends in a longitudinal direction of the tissue placement portion 302. The guide portion 307 guides the cutting blade member 305 so as to move the cutting blade member 305 to a fixed position on the tissue dividing base 301. The cutting blade 306 is disposed at a position where, when the cutting blade set 303 is disposed at a predetermined position on the tissue dividing base 301 by the positioning mechanism and the cutting blade member 305 is moved using the guide portion 307, the cutting blade 306 divides the needle biopsy tissue S placed on the tissue placement portion 302 in the longitudinal direction.
