PACKAGE FOR STORING SEMICONDUCTOR ELEMENT

PROBLEM TO BE SOLVED: To solve the problems of heat produced during operation of a semicon ductor element being not efficiently dissipated to the outside, and a thermal breakdown occurring in a semiconductor element. SOLUTION: The package for storing the semiconductor element consists of a base body 1 having a mounting portion 1a on which the semiconductor element 4 is mounted, a frame-shaped ceramic insulator 2 which is attached on the base body 1 so as to surround the semiconductor element mounting portion 1a and has a wiring layer 6 to which each of electrodes of the semiconductor element 4 is connected, and a cover body 3 which hermetically seals the inside of the frame-shaped insulator 2. The base body 1 is a sintered porous body which is composed of molybdenum powders of particles of an average diameter of 50 μm to 10 μm without particles of a diameter of 25 μm or less and is impregnated with copper, and the sintered porous body made of molybdenum is of 80 to 95 wt.% and the copper is of 5 to 20 wt.%.