The present invention relates to a microorganism having a reduced or inactivated activity of a protein according to any one of the following [1] to [3] and improved productivity of lacto-N-triose II or an oligosaccharide having a lacto-N-triose II (LNTII) skeleton as compared with a parent strain: [1] a protein consisting of the amino acid sequence represented by SEQ ID NO: 2 or 4, [2] a mutant protein having an oligosaccharide transporting activity and consisting of an amino acid sequence in which 1 to 20 amino acids are deleted, substituted, inserted, or added in the amino acid sequence represented by SEQ ID NO: 2 or 4, and [3] a homologous protein having an oligosaccharide transporting activity and consisting of an amino acid sequence having an identity of 90% or more with the amino acid sequence represented by SEQ ID NO: 2 or 4.