An optical printer head (1) capable of preventing catching between a filter holder (8) and a luminous tube (2) to prevent production of dust and attaining replacement of the luminous tube (2) without exposing filters to an ambient atmosphere. A filter holder (8) is arranged separately from the light source (2) and a selfoc lens array (14), to prevent production of dust from the filter holder (8) due to contact of the filter holder (8) with the light source (2) and the selfoc lens array (14). A base (9) is arranged so as to receive only the filter holder (8) from being exposed to an ambient atmosphere, resulting in dust being kept from adhering to the filters. A pair of light passages (12,13) are formed on a light path and closed with a light-permeable cover (15) to sealedly close the base (9), thereby preventing dust from intruding into the base (9) during replacement of the light source (2).