Abstract: In an acceleration estimation device for estimating acceleration of a vehicle, a Karman filter for a constant speed estimates x-direction acceleration offset and z-direction acceleration offset when a motorcycle is stopped and is traveling at constant speed. An offset storage stores an x-direction acceleration offset estimated value and a z-direction acceleration offset estimated value. An offset corrector corrects an x-direction acceleration and a z-direction acceleration on the basis of the x-direction acceleration offset estimated value and the z-direction acceleration offset estimated value when the motorcycle is accelerated and decelerated. A Karman filter for acceleration/deceleration estimates the pitch angle of a vehicle body when the motorcycle is accelerated and decelerated. An acceleration corrector obtains an X-direction acceleration and a Z-direction acceleration on the basis of the estimated pitch angle.