A webbing take-up device comprising: a spool that takes up a webbing worn by an occupant and that is rotated in a pull-out direction by the webbing being pulled out; a rotatable locking section that is provided so as to be rotatable as a unit together with the spool and so as to be displaceable in a rotation-radial direction of the spool; a fixed locking section that is provided at an outer side of the rotatable locking section in the rotation-radial direction of the spool, and that the rotatable locking section engages with resulting in pull-out direction rotation of the spool being locked; a restricting section (24, 26) that restricts displacement of the rotatable locking section toward the fixed locking section; and a displacement section (24, 26) that is actuated in a vehicle emergency so as to displace the rotatable locking section toward the fixed locking section against the restriction of displacement of the rotatable locking section by the restricting section, the restricting section (24, 26) being configured to apply to the rotatable locking section a restricting force that is set such that: - in a normal state that is not a vehicle emergency, displacement of the rotatable locking section toward the fixed locking section is restricted by the restricting section (24, 26) so that unwanted engagement of the rotatable locking section with the fixed locking section is thereby suppressed, - the rotatable locking section is displaced toward the fixed locking section by an inertial force that spins the rotatable locking section about its own center of rotation when the displacement section is deactivated and the spool has been rotated in the pull-out direction with an angular acceleration greater than a predetermined angular acceleration. a spool that takes up a webbing worn by an occupant and that is rotated in a pull-out direction by the webbing being pulled out; a rotatable locking section that is provided so as to be rotatable as a unit together with the spool and so as to be displaceable in a rotation-radial direction of the spool; a fixed locking section that is provided at an outer side of the rotatable locking section in the rotation-radial direction of the spool, and that the rotatable locking section engages with resulting in pull-out direction rotation of the spool being locked; a restricting section (24, 26) that restricts displacement of the rotatable locking section toward the fixed locking section; and a displacement section (24, 26) that is actuated in a vehicle emergency so as to displace the rotatable locking section toward the fixed locking section against the restriction of displacement of the rotatable locking section by the restricting section, the restricting section (24, 26) being configured to apply to the rotatable locking section a restricting force that is set such that: - in a normal state that is not a vehicle emergency, displacement of the rotatable locking section toward the fixed locking section is restricted by the restricting section (24, 26) so that unwanted engagement of the rotatable locking section with the fixed locking section is thereby suppressed, - the rotatable locking section is displaced toward the fixed locking section by an inertial force that spins the rotatable locking section about its own center of rotation when the displacement section is deactivated and the spool has been rotated in the pull-out direction with an angular acceleration greater than a predetermined angular acceleration. - in a normal state that is not a vehicle emergency, displacement of the rotatable locking section toward the fixed locking section is restricted by the restricting section (24, 26) so that unwanted engagement of the rotatable locking section with the fixed locking section is thereby suppressed, - the rotatable locking section is displaced toward the fixed locking section by an inertial force that spins the rotatable locking section about its own center of rotation when the displacement section is deactivated and the spool has been rotated in the pull-out direction with an angular acceleration greater than a predetermined angular acceleration.