To provide an application liquid for formation of an interlayer packed bed of a three-dimensional integrated circuit, which can form, at a time of a B-stage heat treatment, a homogenous B-stage film from a coated film formed on a semiconductor substrate by evaporating and removing an organic solvent at a moderate evaporation rate by application; and which can form a favorable interlayer packed bed layer by heat hardening the B-stage film.

An application liquid for formation of an interlayer packed bed layer of a three-dimensional integrated circuit, includes: a thermosetting resin (A) which has a heat transfer coefficient of 0.2 W/mK and over, melt viscosity at 50°C of 500 Pa s and over, and melt viscosity at 120°C of 100 Pa s and under; an inorganic filler (B) which has a heat transfer coefficient of 2 W/mK and over, an average grain size of not less than 0.1 μm and not more than 5 μm, and a maximum grain size of 10 μm and under; a surface-active agent (D); and an organic solvent (E) in which a ratio T1/T2 between a boiling point T1 and a heating temperature T2 in a B-stage process is 1 and over.