To provide a catalyst cleaning device capable of easily cleaning an exhaust gas purifying catalyst for an automobile.

This catalyst cleaning device 10 includes a case 12 consisting of an outside case 12a and an inside case 12b. A catalyst unit 40 is placed on a catalyst unit receiving base 14 inside the inside case 12b. From a nozzle 18 extending from an injection port 16, a solvent is sprayed to the catalyst 42 to dissolve sludge and the like sticking to the catalyst, and then, the solvent is discharged from a discharge port 20. Subsequently, the case 12 is filled with water fed from the nozzle 18, and the water is heated by a heater 32. A vibration plate 26 in an ultrasonic generator 24 is vibrated, and the catalyst is cleaned with vibration by the water and ultrasonic waves. After the water is drained, steam is blown to remove water, and hot air is supplied by means of a fan 36 to dry up the catalyst 42.