The applicability of criminal penalty through a condemned sentence is generated by its execution, but this is not a condition to determine its constant character, which refers its execution because it can be interrupted, substituting its unexecuted part with a milder one thanks to the convict’s behaviour. Of course, in this case, it is about the convict’s behaviour which is an adequate one to the execution of the criminal penalty. The execution of the criminal penalty and the observance of obligations which are given through its status and law. The substituting of the institution of unexecuted part of penalty with a milder one is applied only after the establishing of legal conditions which refer to the convict’s personality and this offence. The conditions of application of this criminal institution represent a theoretical and a special practical interest, but not in the latter case, it represents the consequences substituting the unexecuted part of the criminal penalty with a milder one.