To estimate a self-position without interrupting a movement locus without using a sensor other than the camera.SOLUTION: An estimation device of the embodiment is provided with an acquisition unit, a first estimation unit, a first calculation unit, a second estimation unit, a second calculation unit, and a determination unit. The acquisition unit acquires an image captured by a camera. The first estimation unit estimates first estimation information from the image. The first calculation unit calculates first reliability indicating the reliability of the first estimation information. The second estimation unit estimates the second estimation information. The second calculation unit calculates a second reliability indicating the reliability of the second estimation information. The determination unit determines at least one of a position and an attitude of the camera from the first and second estimation information based on the first and second reliability, and outputs as a determination processing result at least one of the determined position and attitude. The second estimation unit estimates the second estimation information based on the past determination processing result by the determination unit.SELECTED DRAWING: Figure 2