PURPOSE: To provide a cooling apparatus capable of obtaining low temperature in a short time by defining equilibrium pressure upon hydrogen occulusion of first metal hydride to be lower than equilibrium pressure at low output temperature of second metal hydride.

CONSTITUTION: First metal hydride 3 and second metal hydride having different hydrogen equilibrium pressure at an arbitrary temperature are put in containers 1, 2, which containers are then communicated with each other through a pipe 5 having a valve 6 in the course thereof and are filled with hydrogen gas to construct an intermittently operated cooling apparatus. Herein, temperature and heat capacity of the low equilibrium pressure first metal hydride 3 before hydrogen occulusion reaction, and heat capacity of the container 1 are defined such that the equilibrium pressure of the first metal hydride 3 upon hydrogen occulusion to be lower than the equilibrium pressure of the second metal hydride at cold output temperature. Hereby, temperature rise due to heating is suppressed to be lower, and hence low temperature is ensured in a short time.