To provide an X-ray microscopic inspection apparatus capable of performing non-destructive inspection with high resolving power equal to or less than 0.1 .mu.m in a very short period, and largely contributing to the nano-technology field.In the X-ray microscopic inspection apparatus having X-ray generating means for generating an X-ray by allowing an electron beam from an electron source to impinge on a target for X-ray generation, for inspecting an object to be inspected by utilizing the X-ray, a magnetic field superposition lens having a magnetic field generating portion disposed in the vicinity of an electron generating portion of an electron gun is included as a component element of the X-ray generating means. Further, the apparatus includes a liquid metal electron source using liquid metal or a thermal field emission electron source as the electron source, as a component element of the X-ray generating means. Furthermore, the apparatus includes a target with a heat sink using CVD diamond as the heat sink as the target for X-ray generation, as a component element of the X-ray generating means.