PURPOSE: To make it possible to execute cleaning of a filter simply and properly in a range hood ventilation fan.

CONSTITUTION: In a range hood ventilation fan 10 equipped with a filter 13 in a ventilating opening 12, a detector 15 which is constructed of a reflectance sensor monitoring the light reflectance of the surface of the filter and detects the state of pollution of the filter 13, a cleaning request display unit 16 which gives information on the time of cleaning of the filter 13 and a control part which obtains an output of the detector 15 and makes the cleaning request display unit 16 operate on condition that this output exceeds a cleaning request threshold value, are provided.