An electronic component packaging structure includes a circuit board, electronic components mounted on the circuit board and a moisture-proof coating layer covering the electronic components. The moisture-proof coating layer is constituted from a polymer material coating having at least two layers of a lower layer and an upper layer, and the polymer material forming the lower layer has higher swelling property and/or solubility to a repairing solvent that is selected from among hydrocarbon-based solvents than the polymer material forming the upper layer.