A tonearm unit used in a playback device configured to play a phonograph record , the tonearm unit comprising: an arm member having a tip to which a cartridge is attached; and a raising and lowering mechanism configured to raise and lower the arm member with respect to the phonograph record along a predetermined axis (C1), wherein the raising and lowering mechanism includes: a supporting member configured to support the arm member ; a rotating member provided to be rotatable about the predetermined axis (C1) with respect to the supporting member ; characterized in that the raising and lowering mechanism further includes: a first guide portion on the supporting member , the first guide portion extending in a circular arc shape by tilting up from a first guide peak portion to a first guide valley portion along a rotation direction of the rotating member ; and a second guide portion on the rotating member , the second guide portion facing the first guide portion and extending in a circular arc shape by tilting up from a second guide valley portion to a second guide peak portion along the rotation direction, and when the rotating member is configured to rotate with respect to the supporting member , the supporting member is configured to be raised and lowered with respect to the rotating member as a result of the second guide portion sliding along the first guide portion . an arm member having a tip to which a cartridge is attached; and a raising and lowering mechanism configured to raise and lower the arm member with respect to the phonograph record along a predetermined axis (C1), wherein the raising and lowering mechanism includes: a supporting member configured to support the arm member ; a rotating member provided to be rotatable about the predetermined axis (C1) with respect to the supporting member ; characterized in that the raising and lowering mechanism further includes: a first guide portion on the supporting member , the first guide portion extending in a circular arc shape by tilting up from a first guide peak portion to a first guide valley portion along a rotation direction of the rotating member ; and a second guide portion on the rotating member , the second guide portion facing the first guide portion and extending in a circular arc shape by tilting up from a second guide valley portion to a second guide peak portion along the rotation direction, and a supporting member configured to support the arm member ; a rotating member provided to be rotatable about the predetermined axis (C1) with respect to the supporting member ; characterized in that the raising and lowering mechanism further includes: a first guide portion on the supporting member , the first guide portion extending in a circular arc shape by tilting up from a first guide peak portion to a first guide valley portion along a rotation direction of the rotating member ; and a second guide portion on the rotating member , the second guide portion facing the first guide portion and extending in a circular arc shape by tilting up from a second guide valley portion to a second guide peak portion along the rotation direction, and when the rotating member is configured to rotate with respect to the supporting member , the supporting member is configured to be raised and lowered with respect to the rotating member as a result of the second guide portion sliding along the first guide portion . <EOS>