A test terminal block (1) is presented and described, consisting of a series terminal block (2) and a test plug block (3) pluggable onto the series terminal block (2), wherein the series terminal block (2) has a plurality of series terminals (4) arranged one alongside the other and a fastening clamp (5) on either side of the plurality of series terminals (4). The test plug block (3) has a plurality of test plugs (6) connected to one another and a fastening part (7) on either side of the plurality of test plugs (6), the two fastening parts (7) being connected to one another via a handle piece (8). Each series terminal (4) has two current bars (9) which together form a separation point, and each test plug (6) has a contact plug (10) insertable into a separation point. The two fastening clamps (5) each have a clamp housing (11) with a receiving portion (12) and the two fastening parts (7) each have a housing (14) with a corresponding insertion portion (15) insertable into the receiving portion (12). Secure and defined contact conditions for the test terminal block when the test plug block (3) is pulled out of the series terminal block (2) are assured by virtue of the following: the clamp housing (11) of each of the two fastening clamps (5) contains at least two catch elements (16, 17) and the housing (14) of each of the two fastening parts (7) has at least two corresponding mating catch elements (18, 19), which catch elements (16, 17) and mating catch elements (18, 19) together determine two interlocking positions of the fastening parts (7) in the fastening clamps (5), one position arranged after the other in the plug-on direction of the fastening parts (7); and an unlocking element (20) is movably arranged in the housing (14) of each of the two fastening parts (7), which unlocking element can be brought into a first unlocking position and a second unlocking position, the locking of the first interlocking position being released in the first unlocking position and the locking of the second interlocking position being released in the second unlocking position by the unlocking element (20).