An examination method for determining pancreatic tumor type comprising: a first step of detecting the degree of methylation in a 5'-untranslated region or a region comprising a 5'-untranslated region and a translated region of a gene encoding a mucin core protein in a set of genes including the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene in a pancreatic fluid sample from a subject, wherein the 5'-untranslated region or the region comprising a 5'-untranslated region and a translated region in each of the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene comprises the nucleotide sequence as shown in SEQ ID NOs: 1 to 4, respectively; and a second step of identifying a pancreatic tumor, using the degree of methylation as an index value, as being of pancreatic tumor type selected from the group consisting of pancreatic ductal adenocarcinoma, an intraductal papillary mucinous neoplasm of the gastric type, and an intraductal papillary mucinous neoplasm of the intestinal type, wherein the methylated or unmethylated statuses of the genes are evaluated by designating cut-off values for methylated DNA content as 50% for the MUC1 gene, 70% for the MUC2 gene, 50% for the MUC4 gene and 60% for the MUC5AC gene and, the pancreatic tumor is identified as: (a) an intraductal papillary mucinous neoplasm of the gastric type when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene are methylated; (b) an intraductal papillary mucinous neoplasm of the intestinal type when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene are unmethylated; or (c) a pancreatic ductal adenocarcinoma when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, and the MUC4 gene are unmethylated and the 5'-untranslated region or the region comprising a 5'-untranslated region and a translated region of the MUC5AC gene is methylated. a first step of detecting the degree of methylation in a 5'-untranslated region or a region comprising a 5'-untranslated region and a translated region of a gene encoding a mucin core protein in a set of genes including the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene in a pancreatic fluid sample from a subject, wherein the 5'-untranslated region or the region comprising a 5'-untranslated region and a translated region in each of the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene comprises the nucleotide sequence as shown in SEQ ID NOs: 1 to 4, respectively; and a second step of identifying a pancreatic tumor, using the degree of methylation as an index value, as being of pancreatic tumor type selected from the group consisting of pancreatic ductal adenocarcinoma, an intraductal papillary mucinous neoplasm of the gastric type, and an intraductal papillary mucinous neoplasm of the intestinal type, wherein the methylated or unmethylated statuses of the genes are evaluated by designating cut-off values for methylated DNA content as 50% for the MUC1 gene, 70% for the MUC2 gene, 50% for the MUC4 gene and 60% for the MUC5AC gene and, the pancreatic tumor is identified as: (a) an intraductal papillary mucinous neoplasm of the gastric type when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene are methylated; (b) an intraductal papillary mucinous neoplasm of the intestinal type when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene are unmethylated; or (c) a pancreatic ductal adenocarcinoma when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, and the MUC4 gene are unmethylated and the 5'-untranslated region or the region comprising a 5'-untranslated region and a translated region of the MUC5AC gene is methylated. (a) an intraductal papillary mucinous neoplasm of the gastric type when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene are methylated; (b) an intraductal papillary mucinous neoplasm of the intestinal type when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, the MUC4 gene, and the MUC5AC gene are unmethylated; or (c) a pancreatic ductal adenocarcinoma when the 5'-untranslated regions or the regions comprising 5'-untranslated regions and translated regions of the MUC1 gene, the MUC2 gene, and the MUC4 gene are unmethylated and the 5'-untranslated region or the region comprising a 5'-untranslated region and a translated region of the MUC5AC gene is methylated.