A transfer device comprising: an image carrier that is configured to carry a toner image; a nip forming member that is configured to form a transfer nip between the nip forming member and the image carrier by contacting with a front surface of the image carrier; and a transfer bias applying unit that is configured to apply a transfer bias, thereby transferring the toner image carried on the image carrier to a recording material at a position of the transfer nip, wherein the transfer bias applying unit is configured to apply the transfer bias in which an AC component and a DC component are superimposed and in which a peak-to-peak voltage of the AC component is larger than 6 times an absolute value of a voltage of the DC component, wherein the transfer bias applying unit is configured to apply a bias that causes a potential difference including the AC component and the DC component as the transfer bias between a first member and a second member, characterized in that the potential difference satisfies a relation of '1/6×Epp > |Eoff|' between a potential difference Eoff of a DC component of the second member with respect to the first member and a peak-to-peak potential difference Epp of an AC component of the second member with respect to the first member, and a polarity of the potential difference Eoff is opposite to a charged polarity of toner, wherein the image carrier is an intermediate transfer element which faces a latent image carrier and to which a toner image obtained through development performed on the latent image carrier is primarily transferred, the nip forming member is in contact with a front surface of the intermediate transfer element so as to form a secondary transfer nip together with the intermediate transfer element, the first member is a rear-surface abutting member which is in contact with a rear surface of the intermediate transfer element at the secondary transfer nip, and the second member is the nip forming member, wherein the transfer bias applying unit is configured to apply, as the transfer bias, a bias satisfying a relation of 'f> (4/d)×v', where a frequency of the AC component is f [Hz], a nip width is d [mm], and a surface movement velocity of the image carrier or the intermediate transfer element is v [mm/s], the nip width being a contact length of the image carrier and the nip forming member in a surface movement direction of the image carrier at the transfer nip, or being a contact length of the intermediate transfer element and the nip forming member in a surface movement direction of the intermediate transfer element at the secondary transfer nip. an image carrier that is configured to carry a toner image; a nip forming member that is configured to form a transfer nip between the nip forming member and the image carrier by contacting with a front surface of the image carrier; and a transfer bias applying unit that is configured to apply a transfer bias, thereby transferring the toner image carried on the image carrier to a recording material at a position of the transfer nip, wherein the transfer bias applying unit is configured to apply the transfer bias in which an AC component and a DC component are superimposed and in which a peak-to-peak voltage of the AC component is larger than 6 times an absolute value of a voltage of the DC component, wherein the transfer bias applying unit is configured to apply a bias that causes a potential difference including the AC component and the DC component as the transfer bias between a first member and a second member, characterized in that the potential difference satisfies a relation of '1/6×Epp > |Eoff|' between a potential difference Eoff of a DC component of the second member with respect to the first member and a peak-to-peak potential difference Epp of an AC component of the second member with respect to the first member, and a polarity of the potential difference Eoff is opposite to a charged polarity of toner, wherein the image carrier is an intermediate transfer element which faces a latent image carrier and to which a toner image obtained through development performed on the latent image carrier is primarily transferred, the nip forming member is in contact with a front surface of the intermediate transfer element so as to form a secondary transfer nip together with the intermediate transfer element, the first member is a rear-surface abutting member which is in contact with a rear surface of the intermediate transfer element at the secondary transfer nip, and the second member is the nip forming member, wherein the transfer bias applying unit is configured to apply, as the transfer bias, a bias satisfying a relation of 'f> (4/d)×v', where a frequency of the AC component is f [Hz], a nip width is d [mm], and a surface movement velocity of the image carrier or the intermediate transfer element is v [mm/s], the nip width being a contact length of the image carrier and the nip forming member in a surface movement direction of the image carrier at the transfer nip, or being a contact length of the intermediate transfer element and the nip forming member in a surface movement direction of the intermediate transfer element at the secondary transfer nip.