Disclosed are a power conversion apparatus and a power module that can be downsized. Four corners of a power module (300) are fastened to a cooling jacket (19A) from its front surface by a front surface side fastening apparatus. Thereafter, a top and a bottom of the housing (12) are reversed, and nuts are screwed with bolts (350) projecting from the rear face of the cooling jacket (19A) to fastenthe power module (300). That is, on the top surface of the cooling jacket (19A) facing the bolts (350) are arranged an AC terminal (159) of the power module (300), a DC positive electrode terminal connection portion (314a), and a DC negative electrode terminal (316). Accordingly, the power module (300) can be downsized.