A swing analyzing apparatus includes: a three-axis acceleration sensor attached to a tennis racket, for measuring accelerations in the directions of three axes when a swing for hitting a tennis ball is taken with the tennis racket; a three-axis gyro sensor attached to the tennis racket, for measuring angular speeds about the three axes; and an analyzing device. The analyzing device has a receiving function to receive data regarding the accelerations and the angular speeds from the three-axis acceleration sensor and the three-axis gyro sensor; a coordinate axis conversion function to convert relative coordinate axes that are the three axes for the accelerations into absolute coordinate axes on the basis of the angular speeds; and a calculation function to calculate an index of the swing on the basis of accelerations resulting from the coordinate axis conversion.