A patient's skin puncturing device according to the present invention is built of a body and of seated therein a pricking needle assembly and of a push-button arranged in the upper portion of the body. Between the push-button and the pricking needle assembly at least two driving springs are arranged. The driving springs are connected by upper ends with the push-button provided with a pushing face. Between the body and the pricking needle assembly at least two return springs are disposed, which are connected with the body. The pricking needle assembly has a driving face cooperating with the pushing face of the push-button, and in the upper portion has wings which upper surfaces cooperate with the driving springs of the push-button and which lower surfaces cooperate with the return springs, and has outer projections cooperating with inner projections with which the body is provided.