In order to provide a positioning device for the exact positioning of a first optical component relative to a second optical component, with which optical components may be positioned relative to one another in an exact and permanent manner and which allows, in addition, relatively simple adjustment, it is suggested that the positioning device comprise a first fixing element and at least one second fixing element which are guided relative to one another by a guide means such that they can be moved towards one another essentially only in a clamping direction and that the positioning device have at least one support element arranged between them, the position of which relative to the fixing elements can be adjusted in at least one direction transversely to the clamping direction and can be fixed between the fixing elements by way of clamping and that the optical components be held on different ones of the elements adjustable relative to one another.