The week immediately before the current or referenced week; largely equivalent to 'last week' (先週) depending on context.
前の週に比べて売上が10％増えた。
Sales increased by 10% compared to the previous week.
ミーティングは前の週の金曜日に行われました。
The meeting took place on Friday of the previous week.
前の週は忙しくて休めなかった。
I was busy the previous week and couldn't rest.