To provide a surface grinding apparatus in which the dust is less easily scattered outside a dust-proof brush during the sanding treatment.

During the sanding treatment by pressing a sanding wheel 13 against a concrete surface after the placement of the concrete, even when the concrete surface is highly uneven, the dust-proof brush 22 is moved in the axial direction of the brush to the unevenness of the concrete surface, or turned around the axis orthogonal to the axis of the brush, and a gap is less easily formed between the concrete surface and a tip of the dust-proof brush 22. A problem that a part of the dust generated during this work is scattered outside can be solved.