Apparatus for opening and closing two-part material containers, preferably capsules, comprising: a sleeve-like housing comprising a closed first end and an open second end; a seat seizing the lower part of a capsule arranged slideably along a longitudinal axis of the housing; a seat gripping the upper part of the capsule that can be introduced at the open end of the housing during the operation of the apparatus and, furthermore, an actuator moving the lower part and the upper part of the capsule coaxially with the housing and along its longitudinal axis, the actuator being in releasable connection with the seat gripping the upper part of the capsule; characterized in that a flexible element counter-holding the seat against the open end of the sleeve-like housing is inserted between the closed end of the sleeve-like housing and the seat gripping the lower part of the capsule; the seat gripping the lower part of the capsule comprises a centre chamber open towards the closed end of the sleeve-like housing; at the closed end of the sleeve-like housing an actuating member supporting the lower part of the capsule inserted by the actuator into the capsule-seizing seat gripping the lower part of the capsule is embedded in a rotatable manner and penetrating into the centre chamber of the capsule-seizing seat; flexible clamping means fixing temporarily the lower part of the inserted capsule is arranged in the centre chamber of the seat gripping the lower part of the capsule; a sleeve is mounted unrotatably onto the rotatable actuating member, so that it can be pushed along the length of the actuating member; the front surface of one end of the sleeve isconnected to the flexible clamping means; the front surface of the other end of the sleeve comprises at least one wavy projection; at least one forcing means is formed on the rotatable actuating member pushing axially the sleeve on a supporting stud of the actuating member and consequently pressing the flexible clamping means onto the lower part of the capsule inserted into the centre opening of the seat gripping the capsule lower part by the rotation of the actuating member and the sleeve relative to each other. a sleeve-like housing comprising a closed first end and an open second end; a seat seizing the lower part of a capsule arranged slideably along a longitudinal axis of the housing; a seat gripping the upper part of the capsule that can be introduced at the open end of the housing during the operation of the apparatus and, furthermore, an actuator moving the lower part and the upper part of the capsule coaxially with the housing and along its longitudinal axis, the actuator being in releasable connection with the seat gripping the upper part of the capsule; characterized in that a flexible element counter-holding the seat against the open end of the sleeve-like housing is inserted between the closed end of the sleeve-like housing and the seat gripping the lower part of the capsule; the seat gripping the lower part of the capsule comprises a centre chamber open towards the closed end of the sleeve-like housing; at the closed end of the sleeve-like housing an actuating member supporting the lower part of the capsule inserted by the actuator into the capsule-seizing seat gripping the lower part of the capsule is embedded in a rotatable manner and penetrating into the centre chamber of the capsule-seizing seat; flexible clamping means fixing temporarily the lower part of the inserted capsule is arranged in the centre chamber of the seat gripping the lower part of the capsule; a sleeve is mounted unrotatably onto the rotatable actuating member, so that it can be pushed along the length of the actuating member; the front surface of one end of the sleeve isconnected to the flexible clamping means; the front surface of the other end of the sleeve comprises at least one wavy projection; at least one forcing means is formed on the rotatable actuating member pushing axially the sleeve on a supporting stud of the actuating member and consequently pressing the flexible clamping means onto the lower part of the capsule inserted into the centre opening of the seat gripping the capsule lower part by the rotation of the actuating member and the sleeve relative to each other.