1) measuring an expression level of miR-1233-5p in a sample from a subject; and evaluating in vitro whether or not the subject has ovarian tumor using the measured expression level;

2) measuring an expression level of a target gene in a sample from a subject using a kit or device comprising a nucleic acid capable of specifically binding to a polynucleotide of miR-1233-5p or to a complementary strand of the polynucleotide; and evaluating in vitro whether or not the subject has ovarian tumor using both of the measured expression levels and a control expression level from a healthy subject measured in the same way; or

3) Measuring an expression level of a target gene in a sample from a subject using a kit or device comprising a nucleic acid capable of specifically binding a polynucleotide of miR-1233-5p or to a complementary strand of the polynucleotide; and assigning the expression level of the target gene in the sample from the subject to a discriminant, which is capable of discriminatorily determining the presence or absence of ovarian tumor and is prepared with gene expression levels in a sample(s) from a subject(s) known to have ovarian tumor and a sample(s) from a subject(s) without ovarian tumor as a training sample(s), and thereby evaluating in vitro the presence or absence of ovarian tumor.