A method for analyzing gene expression in a cell or a tissue containing a cell, comprising: - a step of preparing a first sample from the cell comprising mRNA expressed from a gene to be analyzed; - a step of preparing a dilution series of absolutely quantified standards for the gene to be analyzed; - preparing a second sample from the cell comprising mRNA expressed from an internal standard gene; - a step of preparing a dilution series of absolutely quantified standards for the internal standard gene; - a step of obtaining a calibration curve for the dilution series of absolutely quantified standards for the internal standard gene, and a calibration curve for the dilution series of absolutely quantified standards for the gene to be analyzed, ∘ wherein each calibration curve is based on an amplification curve obtained from a real-time PCR of the corresponding dilution series of the absolutely qualified standard, wherein the calibration curve shows a relationship between the number of cycles when the amplification curve reaches a constant rate of increase of signal intensity (Ct value) and the amount of amplified DNA; - a step of calculating a copy number of the gene to be analyzed from the corresponding calibration curve based on the Ct value of the mRNA comprised in the first sample, determined by amplifying the mRNA from the first sample; - a step of calculating a copy number of the internal standard gene from the corresponding calibration curve based on the Ct value of the mRNA comprised in the second sample, determined by amplifying the mRNA from the second sample; and - a step of dividing the copy number of the gene to be analyzed by the copy number of the internal standard gene. - a step of preparing a first sample from the cell comprising mRNA expressed from a gene to be analyzed; - a step of preparing a dilution series of absolutely quantified standards for the gene to be analyzed; - preparing a second sample from the cell comprising mRNA expressed from an internal standard gene; - a step of preparing a dilution series of absolutely quantified standards for the internal standard gene; - a step of obtaining a calibration curve for the dilution series of absolutely quantified standards for the internal standard gene, and a calibration curve for the dilution series of absolutely quantified standards for the gene to be analyzed, ∘ wherein each calibration curve is based on an amplification curve obtained from a real-time PCR of the corresponding dilution series of the absolutely qualified standard, wherein the calibration curve shows a relationship between the number of cycles when the amplification curve reaches a constant rate of increase of signal intensity (Ct value) and the amount of amplified DNA; ∘ wherein each calibration curve is based on an amplification curve obtained from a real-time PCR of the corresponding dilution series of the absolutely qualified standard, wherein the calibration curve shows a relationship between the number of cycles when the amplification curve reaches a constant rate of increase of signal intensity (Ct value) and the amount of amplified DNA; - a step of calculating a copy number of the gene to be analyzed from the corresponding calibration curve based on the Ct value of the mRNA comprised in the first sample, determined by amplifying the mRNA from the first sample; - a step of calculating a copy number of the internal standard gene from the corresponding calibration curve based on the Ct value of the mRNA comprised in the second sample, determined by amplifying the mRNA from the second sample; and - a step of dividing the copy number of the gene to be analyzed by the copy number of the internal standard gene.