A packaging substrate having an upper surface and a lower surface, the packaging substrate comprising: a mounting region in which an element is accommodated; and a core substrate in which the mounting region is disposed, wherein the core substrate is selected from a ceramic substrate, a glass substrate, or a combination thereof, and wherein the mounting region comprises: a cavity portion formed by recessing a portion of the core substrate; a cavity portion side surface formed inside the core substrate in a thickness direction of the core substrate to form an outer periphery of the cavity portion; and a first heat dissipation portion disposed adjacent to the outer periphery of the cavity portion, wherein the first heat dissipation portion is a thermal path through which heat of the packaging substrate is transmitted to the outside, wherein the first heat dissipation portion comprises one or more heat dissipation vias each having an area of 5,000 μm 2 to 75 mm 2 when viewed from the upper surface of the packaging substrate, wherein the heat dissipation via has a longitudinal diameter and a transverse diameter, wherein the heat dissipation via has a structure in which at least one of the longitudinal diameter and the transverse diameter is changed in the thickness direction of the core substrate, and a minimum value between the longitudinal diameter and the transverse diameter is greater than or equal to 50 μm. a mounting region in which an element is accommodated; and a core substrate in which the mounting region is disposed, wherein the core substrate is selected from a ceramic substrate, a glass substrate, or a combination thereof, and wherein the mounting region comprises: a cavity portion formed by recessing a portion of the core substrate; a cavity portion side surface formed inside the core substrate in a thickness direction of the core substrate to form an outer periphery of the cavity portion; and a first heat dissipation portion disposed adjacent to the outer periphery of the cavity portion, wherein the first heat dissipation portion is a thermal path through which heat of the packaging substrate is transmitted to the outside, wherein the first heat dissipation portion comprises one or more heat dissipation vias each having an area of 5,000 μm 2 to 75 mm 2 when viewed from the upper surface of the packaging substrate, wherein the heat dissipation via has a longitudinal diameter and a transverse diameter, wherein the heat dissipation via has a structure in which at least one of the longitudinal diameter and the transverse diameter is changed in the thickness direction of the core substrate, and a minimum value between the longitudinal diameter and the transverse diameter is greater than or equal to 50 μm. a cavity portion formed by recessing a portion of the core substrate; a cavity portion side surface formed inside the core substrate in a thickness direction of the core substrate to form an outer periphery of the cavity portion; and a first heat dissipation portion disposed adjacent to the outer periphery of the cavity portion, wherein the first heat dissipation portion is a thermal path through which heat of the packaging substrate is transmitted to the outside, wherein the first heat dissipation portion comprises one or more heat dissipation vias each having an area of 5,000 μm 2 to 75 mm 2 when viewed from the upper surface of the packaging substrate, wherein the heat dissipation via has a longitudinal diameter and a transverse diameter, wherein the heat dissipation via has a structure in which at least one of the longitudinal diameter and the transverse diameter is changed in the thickness direction of the core substrate, and a minimum value between the longitudinal diameter and the transverse diameter is greater than or equal to 50 μm.