A shake amount detection device comprising: an acceleration sensor configured to detect an acceleration which is applied to a body; a vibration period detector configured to detect a vibration period during which vibration that becomes a predetermined acceleration based on an operation of a movable component which is different from the body itself is applied to the body; a velocity variation estimation unit including a first integration unit configured to integrate the acceleration detected by the acceleration sensor, an extraction unit configured to extract an acceleration due to vibration based on an operation of a movable component which is different from the body itself, from among accelerations detected by the acceleration sensor, and a second integration unit configured to integrate the acceleration extracted by the extraction unit, wherein the velocity variation estimation unit is configured to estimate from a difference between an integration result of the first integration unit and an integration result of the second integration unit a first movement velocity which is a component velocity due to vibration of the body due to camera shake during the vibration period; a velocity calculator configured to calculate a second movement velocity that is a velocity of the body, based on the acceleration, and to correct the second movement velocity, based on the first movement velocity estimated by the velocity variation estimation unit, by adding the first movement velocity to the second movement velocity, in a case where the vibration period detector detects as being in the vibration period; and a shake amount calculator configured to calculate an image blur correction amount, which is an image movement amount occurring due to the attitude movement of the body, relative to the vibration applied to the body, based on the second movement velocity corrected by the velocity calculator. an acceleration sensor configured to detect an acceleration which is applied to a body; a vibration period detector configured to detect a vibration period during which vibration that becomes a predetermined acceleration based on an operation of a movable component which is different from the body itself is applied to the body; a velocity variation estimation unit including a first integration unit configured to integrate the acceleration detected by the acceleration sensor, an extraction unit configured to extract an acceleration due to vibration based on an operation of a movable component which is different from the body itself, from among accelerations detected by the acceleration sensor, and a second integration unit configured to integrate the acceleration extracted by the extraction unit, wherein the velocity variation estimation unit is configured to estimate from a difference between an integration result of the first integration unit and an integration result of the second integration unit a first movement velocity which is a component velocity due to vibration of the body due to camera shake during the vibration period; a velocity calculator configured to calculate a second movement velocity that is a velocity of the body, based on the acceleration, and to correct the second movement velocity, based on the first movement velocity estimated by the velocity variation estimation unit, by adding the first movement velocity to the second movement velocity, in a case where the vibration period detector detects as being in the vibration period; and a shake amount calculator configured to calculate an image blur correction amount, which is an image movement amount occurring due to the attitude movement of the body, relative to the vibration applied to the body, based on the second movement velocity corrected by the velocity calculator.