A device for supporting heads of a razor intended to be mounted on the handle of replaceable head razors, the handle having a coupling end for removably coupling a head. The supporting device includes a case element removably engageable with the coupling end, the case element having surfaces contacting, at least partially, the surface of the coupling end, generating a form-fit connection. The case element has attachment members for the engagement into corresponding attachment seats provided on the head. The present invention further relates to a head for razors and to a razor.