A contact determination device includes a sensor measuring a contact degree of a body to be detected with an object, a contact determination unit determining whether the body to be detected is in contact with the object, based on a reference value, and a correction unit correcting the reference value, in which a cumulative value is obtained by accumulating a fluctuation amount of the detection value from a contact start time of the body to be detected with the object during a period in which the body to be detected is in contact with the object, and when the detection value increases as the contact degree increases, the correction unit corrects the reference value, based on a maximum value of the cumulative value, or when the detection value decreases as the contact degree increases, the correction unit corrects the reference value, based on a minimum value of the cumulative value.