According to a photocatalyst module detachably attached to a ceiling type lamp having a light source of a downward light tube structure of the present invention, a photocatalyst module detachably attached to a light source unit of a ceiling type lamp comprises: a light source unit which uses power to emit light in a predetermined wavelength (or wavelength band) and has a structure of a cylindrical light tube； a socket unit which inserts the light source unit from a bottom, supports the same and supplies power to the light source unit； and a frame unit which has a structure coupling to the socket unit to be fixed to a ceiling. The present invention comprises: an attachment structure unit which has an attachment area capable of attachment in a designated geometric structure to a designated light tube area of the light tube structure light source unit inserted from a bottom to the socket unit, and maintains a state attached to the designated light tube area of the light tube structure light source unit by means of a structural characteristic of the attachment area and the friction； and a photocatalyst matter unit which is formed by coating a designated photocatalyst matter on a designated air contacting area among areas of the attachment structure unit or by coating a designated photocatalyst matter on a designated air contacting areas among areas of a contact structure unit provided for being in contact with air in at least one side area of the attachment structure unit. Accordingly, the present invention purifies air in a space where the ceiling type lamp is provided while the ceiling type lamp is used.COPYRIGHT KIPO 2020본 발명의 하향식 광관 구조 광원을 구비한 천정형 전등에 탈부착되는 광촉매모듈에 따르면, 전원을 이용하여 지정된 파장(또는 파장 대역)의 빛을 발광하며 원통형의 광관을 포함하는 구조를 지닌 광원부와, 아래 방향에서 상기 광원부를 삽입하여 지지하며 상기 광원부에 전원을 공급하는 소켓부와, 상기 소켓부와 결합되어 천정에 고정되는 구조를 지닌 프레임부를 구비한 천정형 전등의 광원부에 탈부착 가능한 광촉매모듈에 있어서, 상기 소켓부에 아래 방향에서 삽입된 광관 구조 광원부의 지정된 광관 영역에 부착 가능한 지정된 기하학 구조의 부착 영역을 지니며 상기 부착 영역의 구조적 특징과 마찰력에 의해 상기 광관 구조 광원부의 지정된 광관
