PROBLEM TO BE SOLVED: To provide a cutter head for a shield machine that eliminates a need on bit replacement and bit protection and realizes a long-distance shield compatible with all types of ground, by enabling, for example, switching at will between a fish tail bit for sediment of a center cutter and a roller cutter bit for a rock to suit a soil type, the center cutter posing difficulty in bit replacement to suit a soil type, while the roller cutter bit being one of bits fit for cutting hard objects.SOLUTION: A cutter head of the present invention includes a fish tail bit and a bit for cutting a hard object disposed at a central part of a cutter head of a shield machine, the bit for cutting a hard object being with a position of a bit tip in a traveling direction for cutting a ground (referred to as a cutting height) lower than the cutting height of the fish tail bit. The cutting height of the bit for cutting a hard object may be switched to that higher than the cutting height of the fish tail bit, to suit a type of the ground to be cut.SELECTED DRAWING: Figure 1
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