Spun-bonded nonwoven fabric and sanitary material

A spun-bonded nonwoven fabric, comprising fibers formed of a resin composition that comprises:

• a propylene polymer (A);
• a polymer (B) which is at least one selected from the group consisting of polyolefins, other than the propylene polymer (A), and polyesters;
• and
• a low-molecular-weight olefin polymer having a weight-average molecular weight of from 500 to 30,000,
• wherein:
• the fibers have a sea-island structure,
• the fibers comprise fibers in which a ratio of island phases having a diameter of less than 0.32 μm among island phases at a cross-section perpendicular to an axial direction of the fibers is 60% or higher on a number basis,
• a ratio (SMD/SCD) of a tensile strength (SMD) in a machine flow direction (MD) with respect to a tensile strength (SCD) in a direction (CD) perpendicular to the machine flow direction (MD) is from 2.0 to 5.1,
• a content of the low-molecular-weight olefin polymer is from 1.0% by mass to 5.0% by mass with respect to a total amount of the resin composition,
• a sea phase contained in the sea-island structure comprises the propylene polymer (A), and
• the island phases comprise the polymer (B).