To provide a method for restoring the activity of a zeolite catalyst by simple treatment when an aromatic compound is reacted in a liquid phase using the zeolite catalyst, and a method for facilitating the control of activity restoring operation without performing exothermic operation such as combustion or the like and avoiding the destruction of the crystal structure of zeolite caused by heat, steaming, etc.

In the activity restoring method of the zeolite catalyst used in the reaction of the aromatic compound in the liquid phase, water is adsorbed in the zeolite catalyst at 50C or lower before the zeolite catalyst is subjected to ageing operation at a reaction temperature or below.