To simplify grinding operations when ground material is coarse in particular by letting a stationary sucking action be secured with its suction hood extremely made small in size.

This is a manual guiding type concrete grinder provided with a grinding disc 16 driven by a work spindle 12, and with a hopper shaped suction hood 18 covering the grinding disc 16. The suction hood is provided with a center through-hole 19 for a grinder neck part 14, and with an insertion hole for a fixing screw capable of screwing the fixing screw into the grinder neck part 14 within the cup bottom part 183 of a cup shaped fixing collar 182 continued to the hopper bottom part. At least one air bleed opening 24 is disposed in the hopper outer hood of the hopper portion 181 of the suction hood 18 at inexpensive manufacturing cost, and is formed out of a large area enclosed by a gill shaped cover.