Disclosed therein is an air conditioner for a vehicle with a photocatalytic module, which can purify air introduced into the inside of an air-conditioning case, sterilize and deodorize an evaporator and provide an optimized installation position of a photocatalytic module so that the photocatalytic module can be easily attached and detached and conveniently maintained and repaired. The air conditioner includes: an air-conditioning case having an air inflow port formed at an entrance side, air outflow ports formed at an exit side and an air passageway formed inside the air-conditioning case an evaporator mounted on an air passageway of the air-conditioning case an air blower for blowing inside air of the air-conditioning case and a photocatalytic module disposed at one side of the air-conditioning case, wherein the photocatalytic module includes: a catalyst part which causes photocatalytic reaction by irradiated light to generate radicals and at least one light source part for irradiating UV light toward the catalyst part.
