A robot controlling device includes: a position error calculator calculating a position error between an endpoint position of a robot and a position commanded value for the endpoint position; an external force calculator calculating an external force applied to the endpoint position; a force commanded value generator generating a force commanded value for the endpoint position; a force error calculator calculating a force error between the external force and the force commanded value; a storage storing the compliance model for the endpoint position; a first correction amount calculator calculating a first correction amount for the position commanded value, according to the force error, using the compliance model; and a second correction amount calculator calculating a second correction amount for the position commanded value, on the basis of the first order lag compensation for the first correction amount. The position error calculator calculates the position error, using the second correction amount.