The invention relates to the technical field of measuring electric and magnetic properties, and specifically relates to a sample holder (1) to be connected to a device (2) for supporting a sample holder in order to measure the dielectric and/or magnetic properties of a sample (3), said supporting device (2) comprising: first and second connectors (4, 5) suitable for allowing an electromagnetic wave to pass therethrough, and for being connected to a means (6) for transmitting the electromagnetic wave and to a means (7) for circulating the electromagnetic wave after passing through the supporting device (2) and the sample holder (1), respectively, which is suitable for transmitting all or part of the electromagnetic wave from the first connector (4) to the second connector (5) according to a reference axis (x) and for being removably arranged therebetween, the sample holder (1) comprising an outer tubular body (11) that is coaxial to said reference axis (x), and a cavity (8) in which the sample (3) is to be housed, the sample holder further comprising sidewalls (9) positioned transversely to the reference axis (x) on either side of the cavity (8), which said walls thus laterally seal