Warming and ventilating fan used in bathrooms

The invention provides a warming and ventilating fan used in bathrooms. The fan comprises a frame, a fan motor arranged in the frame, a snail shell covering the motor and a signal receiver box, a wind path switching board control motor box and a circuit board box which are arranged outside the snail shell and are used for containing electrical components, wherein at least two of the three boxes are communicated by a seal channel to form a whole. The warming and ventilating fan has the following advantages: the air with higher moisture can be prevented from invading the boxes containing the electrical components even if such moisture-proofing measure as pouring or surface coating is not adopted; the cost is lowered; and the assembly efficiency is improved.