A thermal analysis method includes: setting, by a processor, a first node to a first component and second nodes to a second component from among components of an electronic device, based on design information of the electronic device; assigning thermal information including a second temperature and a second heat quantity to each of the second nodes, based on a first temperature and a first heat quantity of each of areas of the second component; calculating a first thermal resistance between adjacent nodes included in the second nodes, based on the thermal information; calculating a second thermal resistance between the first node and each of the second nodes, based on the design information to generate a thermal network including the first node, the second nodes, the first thermal resistance, and the second thermal resistance; and performing thermal analysis using the thermal network.