The present invention provides a connective tissue body formation substrate which can form a film-like connective tissue having a desired thickness and both surfaces in a desired surface condition without prolonging the time required for formation of the connective tissue. Specifically, two tissue formation surfaces 2a and 2b are faced with each other with a tissue formation space 3 being interposed therebetween. A slit 9 is formed in the tissue formation surface 2b so that the tissue formation space 3 communicates with an outside of the substrate. A connective tissue body formation substrate 1 is installed in an environment where a biological tissue material is present. A connective tissue intrudes into the tissue formation space 3 from the slit 9. Both surfaces of the film-like connective tissue are formed so as to match the substrate surface.
