There is provided an electric-power conversion apparatus in which smoke emission, a burnout, and short-circuiting can be suppressed even when a fuse portion is melted by an excessive current and in which it is made possible that heat generated in the fuse portion is less likely to be transferred to the electric power semiconductor device. The electric-power conversion apparatus includes a fuse portion formed in an electrode wiring member, a fuse resin member that covers the fuse portion, and a sealing resin member that seals an electric power semiconductor device and the fuse portion in a case. Along a current-flowing direction, the fuse portion includes an upstream-side first step portion whose cross-sectional area is smaller than that of the portion at the upstream side thereof, a second step portion whose cross-sectional area is smaller than that of the upstream-side first step portion, and a downstream-side first step portion whose cross-sectional area is larger than that of the second step portion but is smaller than that of the portion at the downstream side thereof.