INSULATED WIRE

Provided is an insulated wire that can inhibit a decrease in adhesion between an insulation film including pores and a conductor. The insulated wire (1) comprises a conductor (3) having a long shape, and an insulation film (5) including multiple pores (7) and covering the conductor (3). The opening area ratio SR measured by a method below is 20% or less. The method of measuring the opening area ratio SR: peeling the insulation film (5) from the conductor (3); obtaining a SEM image showing an interface on a conductor (3) side in the insulation film (5) peeled; calculating an area S1 of an observation region that is at least a part of the SEM image; and an area S2 of portions where the multiple pores (7) are open in the observation region; and calculating the opening area ratio SR by the following Formula (1). SR=S2/S1×100.