An analyzing apparatus (2; 202; 402) configured to analyze a tennis swing in a groundstroke, a volley, or a serve, comprising: a triaxial acceleration sensor (28; 2111) "attached to a tennis racket (12; 210; 410) including a grip (20; 306; 412) and a head (14; 303; 414), and configured to measure acceleration in each direction of three axes when a swing for hitting a tennis ball is performed with the tennis racket; a triaxial gyroscope (30; 2112) attached to the tennis racket (12; 210; 410) and configured to measure angular velocity about each of three axes when the swing for hitting a tennis ball is performed; and an analyzing device, the analyzing device having: a reception function for receiving data" related to the acceleration and the angular velocity from the triaxial acceleration sensor and the triaxial gyroscope; a coordinate axis conversion function for converting a relative coordinate axis of the acceleration into an absolute coordinate axis based on the angular velocity; a calculation function for calculating a head velocity component ratio as a swing indicator based on acceleration resulting from the coordinate axis conversion, and the head velocity component ratio being a ratio of V(hz) and V(hx), V(hx) being a head velocity component in x axis direction which is a direction of a sideline of a tennis court, and V(hz)being a head velocity component in z axis direction which is a vertical direction, and the calculated swing indicator is output to an output unit. a triaxial acceleration sensor (28; 2111) "attached to a tennis racket (12; 210; 410) including a grip (20; 306; 412) and a head (14; 303; 414), and configured to measure acceleration in each direction of three axes when a swing for hitting a tennis ball is performed with the tennis racket; a triaxial gyroscope (30; 2112) attached to the tennis racket (12; 210; 410) and configured to measure angular velocity about each of three axes when the swing for hitting a tennis ball is performed; and an analyzing device, the analyzing device having: a reception function for receiving data" related to the acceleration and the angular velocity from the triaxial acceleration sensor and the triaxial gyroscope; a coordinate axis conversion function for converting a relative coordinate axis of the acceleration into an absolute coordinate axis based on the angular velocity; a calculation function for calculating a head velocity component ratio as a swing indicator based on acceleration resulting from the coordinate axis conversion, and the head velocity component ratio being a ratio of V(hz) and V(hx), V(hx) being a head velocity component in x axis direction which is a direction of a sideline of a tennis court, and V(hz)being a head velocity component in z axis direction which is a vertical direction, and the calculated swing indicator is output to an output unit. a reception function for receiving data" related to the acceleration and the angular velocity from the triaxial acceleration sensor and the triaxial gyroscope; a coordinate axis conversion function for converting a relative coordinate axis of the acceleration into an absolute coordinate axis based on the angular velocity; a calculation function for calculating a head velocity component ratio as a swing indicator based on acceleration resulting from the coordinate axis conversion, and the head velocity component ratio being a ratio of V(hz) and V(hx), V(hx) being a head velocity component in x axis direction which is a direction of a sideline of a tennis court, and V(hz)being a head velocity component in z axis direction which is a vertical direction, and the calculated swing indicator is output to an output unit.