A method of synthesizing a cDNA chain using an insoluble carrier having on the surface thereof a polymer substance containing a first unit having a group derived from a phosphoric ester composing the hydrophilic portion of phospholipid, and a second unit having a group derived from carboxylic acid having an electron-attractive substituent bound to a carbonyl group, which includes immobilizing a polynucleotide for DNA elongation; bringing a solution containing an RNA fragment, nucleotide monomers, and a reverse transcriptase or an enzyme having polymerase activity into contact with the surface of the insoluble carrier; and allowing the polynucleotide for DNA elongation immobilized on the surface of the carrier to elongate using the RNA fragment contained in the solution as a template, to thereby form a single-strand cDNA.