A liquid-filled vibration isolating device, comprising: a core member to be connected to one of a vibration generating body and a vibration transmitting body; a cylindrical member to be connected to the other body; an elastic member connecting the cylindrical member at one end thereof to the outer periphery of the core member in a fluid-tight manner; a diaphragm attached to the other end of the cylindrical member in a fluid-tight manner; a fluid chamber configured as a space defined inside the diaphragm, the space being filled with an incompressible liquid; and a partition member (9, 19) partitioning the fluid chamber into a primary liquid chamber on the core member side and a secondary liquid chamber on the diaphragm side, the partition member (9, 19) having a membrane, a membrane support supporting the membrane, a membrane retainer for restricting, in cooperation with the membrane support, a deformation amount or a displacement amount of the membrane, and a limit passage communicating the primary liquid chamber with the secondary liquid chamber, the membrane support and the membrane retainer each having a through hole penetrating therethrough in a direction toward the primary and secondary liquid chambers (7, 8), respectively, wherein at least one of the membrane support and the membrane retainer has the through hole sectioned into a plurality of windows by one or more beams each having a curved or deflected shape in a plane perpendicular to the thickness direction of the partition member (9, 19), wherein the through hole in which the beams are arranged is circular in shape, characterised in that the beams are each curved in an arc-like shape in the plane, and the arc has a curvature radius R which is 0.5 to 2.0 times the radius D/2 of the through hole. a core member to be connected to one of a vibration generating body and a vibration transmitting body; a cylindrical member to be connected to the other body; an elastic member connecting the cylindrical member at one end thereof to the outer periphery of the core member in a fluid-tight manner; a diaphragm attached to the other end of the cylindrical member in a fluid-tight manner; a fluid chamber configured as a space defined inside the diaphragm, the space being filled with an incompressible liquid; and a partition member (9, 19) partitioning the fluid chamber into a primary liquid chamber on the core member side and a secondary liquid chamber on the diaphragm side, the partition member (9, 19) having a membrane, a membrane support supporting the membrane, a membrane retainer for restricting, in cooperation with the membrane support, a deformation amount or a displacement amount of the membrane, and a limit passage communicating the primary liquid chamber with the secondary liquid chamber, the membrane support and the membrane retainer each having a through hole penetrating therethrough in a direction toward the primary and secondary liquid chambers (7, 8), respectively, wherein at least one of the membrane support and the membrane retainer has the through hole sectioned into a plurality of windows by one or more beams each having a curved or deflected shape in a plane perpendicular to the thickness direction of the partition member (9, 19), wherein the through hole in which the beams are arranged is circular in shape, characterised in that the beams are each curved in an arc-like shape in the plane, and the arc has a curvature radius R which is 0.5 to 2.0 times the radius D/2 of the through hole.