An angle adjusting device configured to support an operations panel so that up and down rotation of the operations panel against an apparatus main body can be made in a designated angle range and configured to adjust a rotational angle of the operations panel in up and down directions against the apparatus main body, the angle adjusting device includes i) a fixing member fixed to the apparatus main body, ii) a rotation member where the operations panel is provided, the rotation member being provided to the fixing member so as to be rotated with respect to a designated rotation shaft in the designated angle range, iii) a lock mechanism configured to lock rotation of the rotation member against the fixing member with respect to the rotation shaft, at one or more parts in the designated angle range, by using a force other than a frictional force between the fixing member and the rotation member, and iv) a setting mechanism configured to set a lock-on state and lock-off state of the lock mechanism.