PURPOSE: To stably fit a filter to a ventilating device with a simple structure.

CONSTITUTION: A ventilation port 15a is formed on the filter fitting wall 15 of a ventilating device 1. A pair of hook pieces 16, 17 are provided across the ventilation port 15 on the fitting wall 15. The hook pieces 16, 17 have an L-shaped cross section, they are extended in the longitudinal direction of a main body 10, and they form storage grooves 18, 19 in cooperation with the fitting wall 15. A filter 25 is installed along the fitting wall 15, and the upper and lower edge sections are stored in the storage grooves 18, 19. The filter 25 is pressed and supported by a filter pressing frame 60. The upper edge section of the filter pressing frame 60 is stored in the upper storage groove 18, then it is slid downward along the filter 25, and the lower edge section is stored in the lower storage groove 19.