To provide the power tool wherein no powder and dust enters its switch during operation under a powder and dust condition.

A grip hollow part 48 and an air intake chamber 50 is adjacent to each other through a partitioning wall. To close a work hole 54 formed in the wall, a sponge sheet 66 is arranged. Accordingly, even in the case that the chamber is in a negative pressure condition upon operation of a grinder 30, the part 48 is not in the negative pressure condition substantially. As a result, no air including powder and dust is taken in from an opening 62 or the like formed at a handle 32. Namely, at the operation of grinder 30, entering of powder and dust in a contact of a switch 60 or a movable part can be prevented.