PURPOSE: To provide a ventilating device capable of ventilating chambers on both sides of a partitioning wall with a simple execution of works and a small installation space by providing a blasting passage having an opening part opening to both chambers within a partitioning wall.

CONSTITUTION: By rotating a fan 10 by means of a motor 11, air within a chamber A and a chamber B enters into a partitioning wall 1 from opening parts 6 and 7 at the upper parts of wall plates 3 and 4, passing through a space 5, a dust-collecting filter 14 and a deodorizing filter 15 and being discharged into chambers A and B through opening parts 8 and 9 formed at the lower parts of wall plates 3 and 4 on both surfaces of the partitioning wall and being circulated. In this manner, one ventilating device can perform air circulation of two chambers A and B at the same time. Since a blasting passage, a space 5 and a filter 10 are provided within the partitioning wall 1, there is no need to later execute a fan and a blasting passage, and execution of warks is simple. Further, since no large installation space is required, and the space is effectively utilized, and the outer box does not project within the chamber so that a clear wall surface can be secured. It is preferable to provide an outdoor opening part opening from the blasting passage to the outdoor.