Flux and solder paste

A flux comprising:

• rosin;
• a solvent;
• a thixotropic agent;
• at least one first activator selected from the group consisting of a piperidine hydroiodide and a pipecholine hydroiodide,
• wherein a content of the first activator is 0.01% by mass or more and 1.5% by mass or less with respect to a total mass (100% by mass) of the flux;
• and
• a second activator other than a piperidine hydroiodide and a pipecholine hydroiodide,
• wherein the second activator includes a compound (Tp) having a benzenethiol skeleton in which one or more hydrogen atoms on a benzene ring are substituted with a mercapto group (—SH).