Abstract: [Problem] To provide a method of manufacturing a piezoelectric oscillator capable of preventing poor DLD characteristics that tend to occur in the piezoelectric oscillator including a piezoelectric resonator element and an IC chip that are sealed in the same package. [Means to Solve the Problem] A step of chemically polishing a surface without an integrated circuit of a silicon wafer 31 (step S2), a step of cleaning the silicon wafer 31 (step S3), a step of cutting the silicon wafer 31 into individual pieces of IC chip 6 (step S5), a step of bonding the IC chip 6 facing downwards in a recessed section of an insulating container, a step of mounting a piezoelectric resonator element in the insulating container, and a step of sealing with metal cover are included.