This paper focuses on the windshield part, which affects the quietness of the interior of an electric vehicle. Sound-insulating glass is extremely effective in reducing high-frequency sound transmitted through the windshield [1]. At the initial stage of automobile development, the shape, dimensions, etc. are not determined. Even under such circumstances, it is necessary to propose basic specifications for soundproofing that satisfy the target values for vibration and noise. The 1D model comes into play in this case. Therefore, the purpose of this paper is to construct a 1D model of the sound-insulating glass of the windshield. The 1D model is a three-layer spring-mass model in which the glass part is the mass and the interlayer film part is the viscoelastic. The validity of the constructed model was verified by comparing the transmission loss with analysis results from a commercially available solver using the Finite Element Method (ACTRAN) and a commercially available solver using the Statistical Energy Analysis method (VA-one) [2–5]. Using the obtained transmission loss, we created a two-element SEA model in Matlab for the sound field outside the vehicle and the sound field inside the vehicle through the windshield and considered the influence on the interior sound caused by the difference in temperature outside and inside the vehicle [6]. Based on these considerations and analysis results, we verified the usefulness and value of the 1D model constructed in this paper.