Provided are a semiconductor module in which bonding properties between an insulated substrate and a sealing resin is improved and a method for manufacturing the semiconductor module. A semiconductor module 50 is provided with: an insulated substrate 23; a circuit pattern 24 that is formed on the insulated substrate; semiconductor elements 25, 26 that are joined on the circuit pattern; and a sealing resin 28 for sealing the insulated substrate, the circuit pattern, and the semiconductor elements. The surface 23a of the insulated substrate in a part where the insulative substrate and the sealing resin are bonded to each other, is characterized in that, in a cross section of the insulated substrate, the average roughness derived in a 300-μm wide range is 0.15 μm or greater and the average roughness derived in a 3-μm-wide range is 0.02 μm or greater.