Spacer particles for a resin composition layer have a compressive strength at 10% compressive deformation at room temperature of 0.05 to 10 MPa or a compressive strength at room temperature of 0.01 to 2 N determined as a compressive load at 10% compressive deformation when the spacer particles are added into the resin composition layer so that a resin composition layer contains 48% by mass of the spacer particles, have a rate of change in compressive strength at 10% compressive deformation by a temperature change from room temperature to 50°C of 5% or less, a rate of change in compressive strength at 10% compressive deformation by a temperature change from -20°C to room temperature of 30% or less, or a rate of change in compressive strength by a temperature change from -50°C to 50°C of 15% or less determined as a compressive load at 10% compressive deformation, when the spacer particles are added into the resin composition layer so that a resin composition layer contains 48% by mass of the spacer particles, and have a volume average particle diameter of 2 to 200 µm and a coefficient of variation in particle diameter of 15% or less.