To obtain a comfortable feeling of sitting without deteriorating ventilation.

An air blowing device 1 for seat consists of a seat mat 2 which has air channels inside and a hose 3 connected to an air conditioner mounted in a car. The seat mat is made by connecting mat elements 7 and flexible tubes 8 alternately. There is a space formed between the tubes 8 and a seating face. When the user sits on the seat mat 2, the tubes 8 bend and the seat mat 2 deformes along the body of the user and therefore the user can obtain a comfortable feeling of seating. Since the body of the user is brought into contact mainly with the mat elements 7, load on the seat mat 2 is supported by the mat elements 7. Therefore, the tubes 8 are not destroyed and the air flow does not become stagnant. Furthermore, the mat elements 7 have sufficient strength and the air channels are not destroyed and there is no deterioration in ventilation.