A fastening apparatus includes a fastening device (1, 3) that heats in a non-contacting state, and then applies pressure to, a shaft part (11b) or shaft body (111) while it is inserted through the through holes (W10, W20) of workpieces (W1, W2), thereby forming at least a second head part (11c) of a fastener (11). The fastening device (1, 3) includes: a fastening die (15) that forms the second head part (11c); and a shaft-part pressure-applying device (9) that applies the pressure to the fastening die (15). A determining device (5) determines whether the fastener (11) is defective or not by calculating a load curve defined by the time and the load during which the pressure was applied and then determining whether an amount of change per unit of time in the load curve after a reference load has been exceeded is within a range of a predetermined reference value.