A diaper for collecting biological samples relates to light industry, and more particularly to a diaper for use in medical examinations and in diagnosing a person's state of health on the basis of an analysis of secretions and/or excreta of the individual. The technical aim of the invention is to create a diaper for the quick and efficient collection of biological samples, the use of which is not restricted by a particular type of indicator substance, and the structural characteristics of which provide for simple, convenient and efficient use. The present diaper (1) for collecting biological samples consists of at least a secretion and/or excreta absorbing base and a detachable absorbing layer (3). The secretion and/or excreta absorbing base of the diaper is provided with at least one through-hole (2). The hole is hermetically sealed on the outside by a sampling element consisting of the detachable absorbing layer and also of a water-impermeable layer (4) and a retaining layer (5).