A method for providing virtual contents in a virtual space based on a common coordinate system includes: detecting a base marker for identifying a fixed point of an actual operation space, and a target marker for identifying an actual operation object, from initial image data indicating an initial state of the actual operation object in the actual operation space; calculating an initial model matrix of a target marker expressing an initial position and orientation of the target marker, and a model matrix of the base marker expressing a position and an orientation of the detected base marker in a virtual operation space having a common coordinate system which has the detected base marker as a reference; and calculating a current model matrix of the target marker expressing a current position and orientation of the target marker by using the calculated model matrix of the base marker.