A hole-shape measuring apparatus for measuring a shape of a flush bolt hole provided in a target member which includes a composite material, wherein the flush bolt hole has: a countersunk head portion which is connected to an opening provided in a principal surface of the target member and has a shape in which a diameter decreases as a depth from the principal surface increases, and a constant portion which is connected, at one end, to a bottom portion of the countersunk head portion and is connected, at the other end, to an opening provided in a back surface of the target member and has a constant diameter, wherein the hole-shape measuring apparatus comprises: a hole diameter measuring mechanism (23,32) which is arranged to measure a diameter of the constant portion; and a countersunk head depth measuring mechanism (24,31) which is arranged to measure a depth at a position of the countersunk head portion where its diameter is equal to a reference diameter, as a countersunk head depth, wherein the hole diameter measuring mechanism (23,32) comprises: a hole diameter measuring rod configured so that a hole diameter measuring gauge provided at a tip portion thereof can be inserted into the constant portion at a tip portion, wherein the hole diameter measuring gauge comprises a pair of measuring terminals arranged so as to be pushed inward when the measuring rod is inserted into the constant portion and to displace or a rod arranged to be displaced in a first direction perpendicular to the principal surface of the target member as a result according to the diameter of the constant portion, and a hole diameter measuring sensor arranged to measure the amount of displacement of the rod, wherein the countersunk head depth measuring mechanism (24,31) comprises: a countersunk head depth measuring rod configured so that a tip portion thereof has a diameter which is the reference diameter and can be inserted into the countersunk head portion and displaced according to the countersunk head depth, and a countersunk head depth measuring sensor arranged to measure an amount of the displacement of the countersunk head depth measuring rod, and wherein the hole diameter measuring rod and the countersunk head depth measuring rod are provided so as to be coaxial. a countersunk head portion which is connected to an opening provided in a principal surface of the target member and has a shape in which a diameter decreases as a depth from the principal surface increases, and a constant portion which is connected, at one end, to a bottom portion of the countersunk head portion and is connected, at the other end, to an opening provided in a back surface of the target member and has a constant diameter, a hole diameter measuring mechanism (23,32) which is arranged to measure a diameter of the constant portion; and a countersunk head depth measuring mechanism (24,31) which is arranged to measure a depth at a position of the countersunk head portion where its diameter is equal to a reference diameter, as a countersunk head depth, a hole diameter measuring rod configured so that a hole diameter measuring gauge provided at a tip portion thereof can be inserted into the constant portion at a tip portion, wherein the hole diameter measuring gauge comprises a pair of measuring terminals arranged so as to be pushed inward when the measuring rod is inserted into the constant portion and to displace or a rod arranged to be displaced in a first direction perpendicular to the principal surface of the target member as a result according to the diameter of the constant portion, and a hole diameter measuring sensor arranged to measure the amount of displacement of the rod, a countersunk head depth measuring rod configured so that a tip portion thereof has a diameter which is the reference diameter and can be inserted into the countersunk head portion and displaced according to the countersunk head depth, and a countersunk head depth measuring sensor arranged to measure an amount of the displacement of the countersunk head depth measuring rod, and