Plasticizing device, injection molding device, and screw

A plasticizing device, comprising:

• a drive motor;
• a screw rotated by the drive motor;
• a barrel positioned to face the screw and having a communication hole through which plasticized material flows out to the outside;
• and
• a first heating section configured to heat material, wherein
• the screw includes
• a first screw section that has a facing surface which oppose the barrel and
• a second screw section protruding from the facing surface in a direction of a rotation axis of the first screw section, a tip end of the second screw section being located in the communication hole,
• the second screw section is located to overlap the rotation axis,
• a first groove to which the material is supplied is formed in the facing surface of the first screw section,
• a second groove connected to the first groove is formed on a side surface of the second screw section, and
• in the rotation axis direction, a distance between the tip end of the second screw section and the facing surface of the first screw section is larger than a width of the second screw section.